Three Tips: Simplify, Simplify, Simplify.
Developing fewer features allows you to conserve development resources and spend more time refining those features that users really need. Fewer features mean fewer things to confuse users, less risk of user errors, less description and documentation, and therefore simpler Help content. Removing any one feature automatically increases the usability of the remaining ones.
...the book is a manifesto to make the Web atone for the sins of computers and regain a level of simplicity that can put humanity at peace with its tools once again.